Lime soap grease



Patented Dec. 4, W34

UNITED STATES 1,982,862 mm soar GREASE Walter-D. Hodson, Chicago, m.

No Drawing. Application Serial Deacgmber 9, 1929.

cum. (on. 87-9) The present invention relates to improvements in grease compositions, and more particularly in such compositions composed principally oi a mineral lubricating oil and a lime soap, with .which alkali metal soaps may or may not be incorporated. Anhydrous greases of this character have hitherto been regarded as unsatisfactory because the structure of the grease is readily broken down by mechanical working or by heating, with segregation or sweating oi the oil, and the original structure is not recovered when the grease is again cooled.

In accordance with the present invention, these diillculties are avoided and an anhydrous grease may be produced'containing lime soap as its base in whole or in part and which does not have its structure deleteriously affected by mechanical agitation orby heating and subsequent cooling.

In accordance with the present invention, an

anhydrous lime soap is prepared by saponiflcation of a suitable fat or fatty acid with hydrated lime in usual manner, the resulting soap being heated until substantially water-tree; for example, the temperature may be brought to as high as 250 to 300 F. Atthe same time, complete saponiflcation and uniformity of product is thereby secured.

Relatively large quantities of water may be presout during saponiflcation, as the water is subsequently completely removed. The completeness of saponiflcation and uniformity of product are therebygreatly improved. The fat or fatty acid employed may be any one of those ordinarily used in grease making, in accordance with the hardness and other characteristics of the soap to be obtained. For example, the soap stock may be tallow, stearic acid, oleic acid, fish oil, lard, degras, rosin oil or the like. Instead of saponiiying the selected soap stock with hydrated lime, the de-, sired soap may be madeby double decomposition from an alkali metal soap or the desired soap stock with a soluble calcium salt, the calcium soap being removed and dehydrated by heating as hereinbeiore pointed out.

A suitable viscous mineral oil is then incorporated in the anhydrous lime soap. The mineral oil employed is selected in the usual manner in accordance'with the requirements oi the situation in which the grease is to be employed. Ordinarily, an oil of to sec. Saybolt viscosity at 100 F. is employed,- althoush lighter or heavier oils may be employed, as is customary in the manufacture of greases. The proportion of the lime soap in the mixture may be, as is customary, from 5% upwardly, and ordinarily is from 10 to 25%, depending upon the characteristics desired. in the grease.

The product thus resulting, being anhydrous,

does not have the characteristics of typical lime soap greases. particularly as regards physical structure. The presence of suitable proportions of water secured as is customary in ordinary manufacture of lime soap greases, gives the grease its physical characteristics, but the grease product is physically unstable, tends to sweat or separate out oil on heating, and loses its structure on alternate heating and cooling. In accordance with my invention I avoid these disadvantages in the iollowing manner:

During the intermixture of the soapand the oil, I incorporate a small proportion, say up to 5% and preferably from 1 to 5%, of an organic solvent coupling agent having a boiling point in excess of 85 C. which is a solvent for or completely miscible with the oil. The solvent employed is 01 the type generally designated as lacquer solvents; for example, I have. employed satisfactorily trlethanolamine, dietliyleneglycol, the alkyl ethers of ethyleneglycol and diethyleneglycol such as the monoethyl and monobutyl ethers of ethyleneglycol, the monoethylether oi! diethyleneglycol, the esters of such ethers, such as their acetates, iormates. and the like, ethylenedichloride, and similar solvent compounds. The resultinggrease has the desirable properties or such lime base greases and in addition has the advantage that it is "tabiliaed, and may be melted and congealed and thereupon returns to its original condition. The proportion of the stabilizing solvent material, while ordinarily not above 5%,

is adJusted. to secure the desired stabilizing efiect.

Small proportions 0! water can be subsequently incorporated in the grease, for eiample, from to 1 The grease thereupon becomes thicker and less plastic and assumes a somewhat stringy ,characterb Furthermore, in use, the grease may corporated into the grease ii a mixed base grease is' desired.

I claim:

1. A lime soap grease containing a viscous mineral oil and lime soap of a fatty acid of high molecular weight and a minor proportion of a structure stabilizing oil-miscible solvent.

2. A lime soap grease containing a viscous mineral oil and lime soap and a minor proportion of triethanolamine.-

3. A lime soap grease containing a viscous mineral oil and lime soap and a minor propor- WALTER n; HODSON. 

